A no deposit bonus is a type of promotion offered by online casinos or betting sites, where players can receive a bonus without making a deposit. This means that players can try out the site or specific games without risking their own money. No deposit bonuses usually come in the form of free spins, bonus funds, or a combination of both. However, it's important to read the terms and conditions carefully, as there may be restrictions on how the bonus can be used or withdrawn.